Lamp dimmer



June 30, 1970 J. B. RICHEY 3,518,602

LAMP DIMMER Filed May 29, 1968 INVENTOR. J05EPH 5. P/CHE) .1 W fi m I United States Patent O 3,518,602 LAMP DIMMER Joseph B. Richey, Cleveland Heights, Ohio, assignor of one-fourth jointly, to Ernest R. Vargo and Louis E. Vargo, both of Cleveland, Ohio Filed May 29, 1968, Ser. No. 733,035 Int. Cl. H01c 13/00 US. Cl. 338-73 2 Claims ABSTRACT OF THE DISCLOSURE A lamp dimmer controlled by a rotatable sleeve surrounding the lamp socket. More particularly a lamp dimmer having a male lamp bulb base, a lamp socket, a sleeve surrounding the socket, and a lamp dimming circuit including a variable element such as a resistor, wherein the variable element is provided with a radially extending control arm which engages a slot in the sleeve in order to be controlled thereby.

BACKGROUND OF THE INVENTION This invention relates to lamp dimmers of the type suitable for use with table lamps and the like, and more particularly to mechanical means for initiating a change in light output in such dimmers. Lamp dimmers are well known in the art. In terms of use there are two principal types, one type suitable for wall mounting and the other for insertion into a table lamp or the like between the lamp socket and bulb. Both types are in wide use for light control in homes, offices,waiting rooms and similar places.

The lamp insert type of dimmer generally comprises a male bulb base for insertion into the lamp receptacle, a socket for receiving the lamp bulb therein, a dimmer circuit for controlling the amount of power to the bulb, and a rotatable control knob protruding from the side of the dimmer for setting the light output. The knob may also actuate an on-otf switch for the lamp.

Although such dimmers are widely used they suffer several disadvantages resulting from the use of a protruding knob as the control element. Lamps are. most often used for reading and so are placed adjacent a chair or couch on which the reader sits. The lamp must be positioned so that the control knob on the dimmer is conveniently accessible from the chair or else the reader must grope and fumble to reach it. Even if the lamp is initially placed to make the knob accessible it will invariably be displaced in the course of cleaning or the like. In addition, the lamp base is normally provided with a protruding knob to enable actuation of an on-off switch for the lamp. The presence of two protruding knobs having separate functions on the same lamp is, at best, inconveniently confusing especially to the unfamiliar user in, for example, a waiting room. In addition, the presence of both the lamp switch knob and the dimmer knob detracts from the pleasing appearance of the lamp which has a decorative as Well as a functional purpose.

If the lamp switch-is replaced by an on-oit switch actuated by the dimmer knob so that both on-off control and dimmingar'e controlled by the same knob the confusion to the occasional user' is somewhat alleviated. However, a more familiar user such as a home owner may have determined a light setting exactly suitable to him and desire to leave the dimmer control set at that point without having to readjust the control each time the lamp is turned on. If, however, the lamp on-ofl? switch is actuated by the dimmer knob at one end of its rotational travel then the dimmer knob will have to be repositioned for the desired light setting each time the lamp is turned on. In order to optimize the use of the dimmer to both ice a familiar and nonfamiliar user it is desirable to place the separate functions of on-off control and dimming in separate control elements which are not easily confused.

SUMMARY OF THE INVENTION A general object of my invention is to provide a lamp dimmer that overcomes the difiiculties noted above that are encountered with lamp dimmers having protruding knobs as rotatable control elements. A particular object is the provision of a lamp dimmer having a simple and conveniently operated control element that may be rotated with equal convenience from any position around the lamp.

Other objects are the provision of a lamp dimmer having a control element that is not easily confused with the lamp on-ofi switch and that can remain in one position when the lamp is turned on or off.

Briefly, a preferred embodiment of my invention comprises the combination of a male lamp bulb base, a lamp socket supported above the base, a lamp dimming circuit supported generally between the base and socket and including a variable element such as a resistor or capacitor, a control arm connected to the circuit element for variation thereof, and a sleeve fitted over the socket for rotation thercabout, the sleeve having a slot for receiving therein the end of the control arm.

In operation, the dimmer is inserted between the lamp socket and a lamp bulb. The male bulb base is inserted into the lamp socket and the dimmer socket receives a bulb. Rotation of the sleeve about the socket moves the control arm, varying the element in the dimming circuit and adjusting the light output. The lamp is turned on and oil? by the switch provided on the lamp itself so that the control elements for on-off control and for dimming are not confused.

Since the sleeve is the control element the dimmer may be controlled from any position around the lamp merely by rotating the sleeve about the longitudinal axis of the lamp. Thus, dimming or brightening of the lamp bulb may be accomplished without the inconvenience of groping for a misplaced control knob.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of an assembled lamp dimmer embodying my invention disposed between a lamp base and a bulb for use therewith.

FIG. 2 is an exploded view of the constituent parts of the lamp dimmer of FIG. 1 in elevation, but with the sleeve and a portion of the lamp socket in longitudinal section.

FIG. 3 is a schematic diagram of a lamp dimmer circuit suitable for use in the lamp dimmer embodying my invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A lamp dimmer embodying a preferred form of my invention is shown in FIG. I inserted into the socket of a lamp base-B and having a bulb L inserted into its own socket. The dimmer has no protruding knob but is controlled by rotation of the outer sleeve S about its own longitudinal axis. A knob K on the lamp base B actuates the on-oif switch for the lamp.

In FIG. 2 a male light bulb base 10 is rigidly connected to, and held in spaced relation with, a conventional lamp socket 11 by a metal bar or piece of thick rigid wire 12. The base 10 is exteriorly threaded as at 13 for screwing into a conventional lamp socket. Likewise the lamp socket 11 is interiorly threaded as seen in the sectioned portion at 14 for receiving therein the base of a lamp bulb. Disposed between the plug 10 and the socket 11 are the physical components, designated by square 15, of an electrical circuit for controlling the amount of power input to a lamp disposed in the socket '11. The electrical circuit itself is old and forms no part of the invention but will be described hereinafter to in sure completeness of the disclosure.

The dimmer electrical circuit includes a variable resistor 18 provided with a control arm 20. Resistor 18 is preferably circular in shape and supported by bar 12 in axial alignment with socket 11 so that control arm 20 extends radially outwardly and slightly beyond the circumference of socket 11. Control arm 20 may advantageously have its outer end inclined downwardly in almost a vertical direction and then substantially horizontally a small distance for reasons which will appear more fully hereinafter.

Socket 11 is provided with a circumferentially extending groove 21 in its exterior insulating surface generally parallel to the path of rotation of control arm 20 of variable resistor 18.

A cylindrical sleeve S, which may be composed of Bakelite or a similar insulating material, fits over socket 11. During assembly the inclined portion of control arm 20 is deflected slightly inwardly by sleeve S so that the arms horizontal portion snaps into a slot 22 in sleeve S in working position therewith. In this position the groove 21 in socket 11 is aligned with another slot 23 in sleeve S. A plastic pin or screw 24 is inserted into slot 23 and extends into groove 21. The combination of pin the phase angle at which Triac 27 conducts. Changing of this phase angle results in a change in the average amount of power delivered to filaments 28 and in the brightness of the light therefrom. The maximum and minimum brightness settings for the dimmer are determined by the limits of rotation of sleeve S about socket 11. These limits of rotation in turn are determined by the circumferential length of groove 21.

My lamp dimmer is one of simple construction in which the light may be dimmed or brightened from any position around the lamp without searching for an inaccessible knob. The dimmer is easily installed, does not detract from the appearance of a lamp by adding an un- 24 and groove 21 locks sleeve S onto socket 11 and also I defines the limits of rotation of sleeve S with respect to socket 11. A smaller insulating sleeve 26, when slipped upwardly past base 10 so that its upper portion fits snugly within the lower portion of sleeve S, encloses the lower portions of the electrical components 15 and the bar 12. The assembled dimmer is shown in FIG 1.

Dimming or brightening of the bulb L is accomplished by rotating sleeve S about its own longitudinal axis. Sleeve S may be conveniently rotated from any position about the lamp. Since the lamp on-olf switch is actuated by the knob K and not by the dimmer switch sleeve S may remain at any desired setting when the lamp is turned off.

FIG. 3 is a schematic diagram of a circuit suitable for use in my lamp dimmer. In FIG. 3 a Triac 27 is shown connected in series with the filaments 28 of a lamp bulb and to a source of AC potential 29. A Triac is effectively two silicon controlled rectifiers in inverse parallel. By controlling gate 30 of Triac 27 with a variable phase shift circuit the Triac can be caused to conduct current only during a predetermined interval of each half cycle, positive and negative, of AC line voltage.

A neon bulb 32 and a phase shift circuit consisting of capacitor 33 and resistors 18 and 34 are used to control gate 30 of Triac 27. When the phase shifted voltage across resistors 18 and 34 reaches the breakdown voltage of neon bulb 32 the bulb will conduct and cause Triac 27 to conduct during the remaining portion of the half cycle of applied voltage. By varying resistor 18 Triac 27 is caused to conduct earlier or later in the half cycle of applied voltage. Capacitor 35 serves as a filter, bypassing high frequency transients around the gate control circuit.

It will appear to those skilled in the art that other circuits may be used in my lamp dimmer and that the variable element need not be a resistor. My lamp dimmer may utilize any dimming circuit of suitable size which employs a variable circuit element as the control means.

In operation rotation of the sleeve S about socket 11 rotates control arm 20 of variable resistor 18 to vary sightly protruding knob, and may remain set for any degree of illumination without the necessity of repositioning each time the lamp is turned on.

While I have shown and described a preferred form and embodiment of my invention, the concepts thereof can be employed in other embodiments without departing from the spirit and scope of my invention. Therefore I do not want to be limited in the scope and effect of any patent to the forms of my invention specifically disclosed herein nor in any manner inconsistent with the progress by which the art has been promoted by my invention.

I claim:

1. In a lamp dimmer of the type having a cylindrical threaded plug member for insertion into a lamp socket, a cylindrical socket member supported above said plug member for receiving therein a lamp bulb, and a lamp dimmer circuit supported generally between said members, said circuit including a variable control element, the improvement which comprises a. rotatable control arm connected to said variable element and extending radially outwardly therefrom, said socket member having a groove extending partially around the circumference thereof, and

an insulating sleeve fitted over said socket member and said circuit and extending upwardly past the upper edge of said socket member, said sleeve being rotatable about said socket member, said sleeve having a hole positioned to overlie said groove and having a. pin extending through said hole and into said groove thereby locking said sleeve onto said socket member and limiting rotation of said sleeve about said socket member, said sleeve being connected to the radially outer end of said arm whereby rotation of said sleeve about said socket member within the limits defined by said groove varies the amount of illumination from said bulb.

2. The improvement of claim 1 wherein said arm is resiliently defiectable inwardly and said sleeve has a slot for receiving therein the radially outer end of said arm whereby in assembling said dimmer said arm is deflected inwardly by said sleeve passing over said socket member and snaps into said slot in working position with said sleeve.

References Cited UNITED STATES PATENTS 596,582 1/1898 Felch 338--72 904,826 11/1908 Witt 338-72 1,327,642 1/ 1920 Sykes 338-73 1,720,501 7/1929 Weichelt 33872 3,379,871 1/1966 Peek 338-70 XR FOREIGN PATENTS 581,976 12/ 1924 France. 201,088 1923 Great Britain.

THOMAS J. KOZMA, Primary Examiner 

